1. Field of the Invention
The present invention relates to composite polymers containing nanometer-sized metal particles and manufacturing method thereof, and more particularly, to composite polymers containing nanometer-sized metal particles and manufacturing method thereof, which nanometer-sized metal particles are uniformly dispersed into the polymers, thereby allowing the use thereof as optical, electrical and magnetic materials.
2. Description of the Related Art
In general, nanometer-sized metal or semiconductor particles, i.e., nano-particles, have a nonlinear optical effect. Therefore, composite polymers having the nano-particles dispersed on polymers or glass matrices have attracted people""s attentions in optical materials. Moreover, the nano-particles having a magnetic property are applicable in various ways, for example, a use for an electromagnetism storage medium.
In manufacturing the composite polymers, the nano-particles, which are manufactured by the process of vacuum deposit, sputtering, CVD or sol-gel process, mixed with polymer melt in a high temperature or polymer solution dissolved in a proper solvent and dispersed well in a polymer matrix.
A conventional composite polymers obtained by a conventional method by dispersing nano-particles into the polymer matrix, cannot show satisfactory composite material characteristics because a state of the nano-particles is changed due to a high surface energy of the nano-particles and the nano-particles may easily form agglomeration when dispersed on a matrix, i.e., cause a light scattering in using for nonlinear optics.
Nanometer sized particles, which have a finite size effect, have characteristics different from a bulk state. Various attempts have been tried to manufacture metal particles of nanometer size through various physical and chemical processes that has been known to be reliable, in a monodispersion, and have valence of zero, for manufacturing such fine particles.
Such attempts include the steps of sputtering, metal deposition, abrasion, metallic salt reduction, and neutral organometallic precursor decomposition.
Transition metal particles, such as gold (Au), silver (Ag), palladium (Pd) and Platinum (Pt), manufactured as conventional methods are in the form of aggregated powder state or are sensitive to air and tend to be agglomerated irreversibly.
Such an air sensitivity raises a problem in connection with stability when the metal particles present in a large amount. Moreover, the air sensitivity has another problem that the metal particles are collapsed due to oxidation if the final products are not sealed under a high-priced air blocking state during the manufacturing process.
The irreversible agglomeration of the particles needs a separation process which causes a problem in controlling the particle size distribution in a desired range and prevents formation of a soft and thin film, which is essential for a magnetic recording application field. The agglomeration reduces a surface area, which is chemically active for catalytic action, and largely restricts solubility, which is essential for biochemical label, separation and chemical transmission application field.
With the reasons, to exactly adjust a particle size or to manufacture nano-particles having a mono-dispersion phase is an important object in a technical application field of the nano-materials. Therefore, the nano-particles have been manufactured by physical methods such as mechanical abrasion, metal deposition condensation, laser ablation and electrical spark corrosion, and by chemical methods such as reduction of metallic salt in a solution state, pyrolysis of metal carbonyl precursor and electrochemical plating of metals.
Since several physical or chemical methods cause incompatibility and a permanent agglomeration when metal particles accumulated from a vapor state under appropriate stabilizer transfer fluid or transfer fluid containing the appropriate stabilizer. It is impossible to improve the general process of direct dispersion of nanoparticles into the matrices.
Furthermore, even though the metal particles are manufactured in a mono-dispersion phase state, the particles are agglomerated and not dispersed well due to the heat or pressure generated during the process of dispersing the metal particles in the polymer matrix, the metal particles are not compatible with the polymer matrix and defects are generated on the interface.
It is, therefore, an object of the present invention to provide composite polymers containing nanometer-sized metal particles and manufacturing method thereof, which can keep nanometer-sized metal particles in a well dispersion state in a matrix without a permanent agglomeration.
It is another object of the present invention to provide a simple method, which is capable of easily manufacturing composite polymers in such a manner that the manufacture of nanometer-sized particles and the separate process for composition are performed in-situ.
It is a further object of the present invention to provide a method, which is capable of overcoming a limitation of the amount of metal particles in conventional composite polymers and adjusting the amount of the metal particles in the matrix in a molecule level.
To achieve the object, the present invention provides a method for manufacturing composite polymers containing nanometer-sized metal particles, the method including the steps of: dispersing at least one metal precursor into a matrix made of polymers in a molecule level; and irradiating rays of light on the matrix containing the metal precursors dispersed in the molecular level and reducing and fixing the metal precursors into metals inside of matrix.